The present invention generally relates to audio systems and more particularly to systems for enhancing the sound received by audiences located at varying distances from loudspeakers.
The current state of the art for sound production or sound supporting equipment used in concert halls or in other spaces entails the use of one or more main loudspeaker cluster locations. These are typically located near the physical location of the actual sound source or that of the virtual sound source. Unfortunately nature has provided some impediments for these types of sound systems. In this regard as the sound produced by the loudspeakers travel over distance, distortion of the frequency and time spectrum naturally occur. Also, non-linear type distortions are introduced due to the physics of the air compression and rare fractions by which the sound propagates. Moreover, since the perceived loudness and the sound pressure level decreases with increasing distance from the sound source, in order to achieve the desired sound pressure level (SPL) at remote listener positions substantially more sound pressure must be developed at the source. However, increasing the sound pressure level thereat produces more distortions. Thus, the larger the distance from the sound source to the audience the more acute the problem.
Persons attending concerts in large halls or arenas are becoming more demanding in their desires for high quality sound; they want to have the sound quality delivered to them by public address speaker systems approaching recording studio quality. This places a heavy burden on the large sound system designer. One common approach to achieve that end is utilize what has been referred to as xe2x80x9cdelayed speaker systemsxe2x80x9d in combination with the main loudspeaker system. In particular, additional loudspeakers are provided at remote locations so that they can be located closes to some of the audience than the main loudspeaker(s) or cluster(s). These fixed remote loudspeakers typically have their input signals delayed in time with respect to the signals provided to the main loudspeaker(s)/cluster(s) to synchronize their acoustic output with that arriving from the main loudspeaker(s) or cluster(s).
In an article appearing in the Journal Of The Audio Engineering Society, Vol. 28, No. 10, October 1980, entitled Sound Reinforcement Systems In Early Danish Churches, by Dan Popescu, there are disclosed distributed loudspeaker systems making use of remotely located loudspeakers and delay equipment to synchronize the amplified sound with the direct (e.g., live) sound.
Other approaches for delivering audio to persons within an auditorium are found in the following U.S. Pat. Nos. 2,567,431 (Halstead), 3,235,804 (Mcintosh), and 4,165,487 (Corderman).
While the foregoing approaches to sound enhancement have some aural benefits, they never the less still leave much to be desired from the standpoint of delivering very high quality sound to the remote listeners. Moreover, such systems can become relatively complex, unwiedly and inflexible.
Accordingly, a need exists for an audio enhancement system which overcomes the disadvantages of the prior art.
It is a general object of this invention to provide an audio enhancement system which overcomes the disadvantages of the prior art.
It is a further object of this invention to provide an audio enhancement system for providing augmented sound to persons located at remote distances from main loudspeaker (s) or cluster(s) so that the augmented sound is synchronized with the sound arriving from the main loudspeaker(s)/cluster (s).
It is still a further object of this invention to provide an audio enhancement system for providing augmented sound via personal transducers to persons located at remote distances from main loudspeaker(s)/cluster(s).
It is yet a further object of this invention to provide an audio enhancement system for providing augmented sound via portable equipment to persons using the equipment located at remote distances from main loudspeaker(s)/cluster(s).
It is yet a further object of this invention to provide an audio enhancement system for providing augmented sound via wireless transmission to portable equipment used by persons located at remote distances from main loudspeaker(s)/cluster(s).
These and other objects of this invention are achieved by providing an audio enhancement system and method of use with a sound system producing primary sound from at least one main loudspeaker located at a first position. The primary sound is produced by the main loudspeaker in response to an electrical input signal and is propagated through the air to remote locations, at least one of which is arranged to have a person thereat.
The audio enhancement systems comprises transmitter means, time delay means, and augmented sound producing means. The transmitter means is arranged for effecting the wireless transmission of transmission signal to the augmented sound producing means. The augmented sound producing means produces augmented sound at remote location substantially in time synchronization with the primary sound arrival so that said person perceives the primary and augmented sounds in as a single enhanced sound arrival. The augmented sound producing means comprises receiver means receiving the transmission signal and for providing an electrical signal in response thereto, and transducer means for converting the electrical signal into the augmented sound. The time delay means is arranged to effect the delay of the electrical signal to the transducer means for a predetermined period of time corresponding generally to the time period it takes for the primary sound to propagate through the air from the main loudspeaker to the remote: location.
The method of this invention entails enhancing the sound provided to at least one person located at a first location remote from at least one main loudspeaker. The method comprises providing the person with a portable sound augmentation system comprising a transducer device for providing augmentation sound to that person, providing a main loudspeaker at a first position, providing an audio electrical signal from an audio source for producing primary sound from the loudspeaker in response thereto, and wirelessly transmitting a transmission signal corresponding to the audio electrical signal to the portable sound augmentation system, whereupon the sound augmentation system provides an output electrical signal to the transducer device to produce the augmentation sound at the remote location. The provision of the output electrical signal to the transducer device is delayed by the system for a predetermined period of time corresponding generally to the time period it takes for said primary sound to propagate to said remote location, whereupon said augmentation sound and said primary sound reach the ears of the person in substantial synchronism.